1. Field of the Invention
The present invention relates to a belt hoist wherein a belt is wound around a winding member which is rotationally driven in a normal direction or in a reverse direction to raise or lower or drag a load through the belt.
2. Description of the Prior Art
As shown in FIG. 8 and disclosed by Japanese Laid-Open Utility Model Publication No. Hei 6(1994)-25290, a conventional type belt hoist is structured so that a flat belt B is wound around a winding member A having a shaft insertion bore A1 at the center thereof, with one end portion of the belt B fixed to a winding periphery of the winding member A and the other end portion thereof retaining a hanger for holding a load. For the winding of belt B around the winding member A, the winding member A is provided, on its outer periphery, with a generally L-shaped recess C comprising a stepped portion C1 extending radially inward from the outer periphery, and a belt fixing surface C2 extending from an inner end of the stepped portion C1 in the same direction as a coiling direction X of the belt B around the winding member A and having a width smaller than an inner diameter of the shaft insertion bore A1. In the belt fixing surface C2 of the recess C, a fixing bore D extending toward the shaft insertion bore A1 is bored. After the end portion of the belt B is fixedly mounted on the belt fixing surface C2 with a fastening screw E screwed into the fixing bore D, the free end side of the belt B is drawn out from the belt fixing surface C2 at the side opposite to the stepped portion C1 of the recess C in the same direction as the coiling direction X, and is wound around the winding member A.
When a load is raised up, the winding member A is rotated in the opposite direction to the coiling direction X of the belt B, to take up the belt B on the periphery of the winding member A so as to hoist up the load through the belt B. When the load is lowered down, the winding member A is rotated in the same direction as the coiling direction X of the belt B, to let out the belt B from the winding member A so as to lower down the load through the belt B.
When the load is raised or lowered, a large load acting in the same direction as the coiling direction X is exerted on the belt B. With the conventional type belt hoist described above, since the fixing bore D is bored in the belt fixing surface C2 to extend toward the shaft insertion bore A1 at the center of the winding member A, the depth of the fixing bore D is restricted by the length between the belt fixing surface C2 and the shaft insertion bore A1 and thus is inevitably of limited depth. Because of this, this conventional type belt hoist has a disadvantage that the fixture of the free end portion of the belt to the winding member cannot be well strengthened by use of the fastening screw E screwed into the fixing bore D.